tbuckley/cabot-search huggingface dataset:
BIOM-57. UNRAVELING THE DYSREGULATION OF MIR-17/92 CLUSTER IN AGGRESSIVE PEDIATRIC BRAIN TUMORS: IMPLICATIONS FOR NOVEL THERAPEUTIC STRATEGIES
Authors: Shehbeel Arif, Komal Rathi, Ammar Naqvi, Anne Coyle, Madison Hollawell, Phillip Storm, Adam Resnick, Peter Madsen, Mateusz Koptyra
Journal: Neuro-Oncology (2023)

Abstract The miR-17/92 cluster, commonly referred to as “OncoMir-1,” is extensively studied in cancer due to its oncogenic role, but it has yet to be fully characterized in pediatric brain tumors. In this study, we conduct a comprehensive investigation involving miRNA profiling of 262 pediatric brain tumors, along with sample-matched data from the Pediatric Brain Tumor Atlas, including WGS, RNA-sequencing, proteomics, and phospho-proteomics data. Through miRNA-based unsupervised clustering, we identified four distinct miRNA signatures that transcend histological boundaries. An aggressive cluster (consisting of Medulloblastoma, ATRT, High-Grade Astrocytic Tumors, and some Ependymomas) exhibited the shortest survival and displayed an enriched network of co-expressed miR-17/92 cluster family members and paralogues, specifically miR-106b/25 and miR-106a/363 (p&amp;lt; 0.001). These tumors exhibited significant upregulation of the MIR17HG gene, which encodes the miR-17/92 cluster of miRNAs (p&amp;lt; 0.001). Further exploration of the upstream regulatory mechanisms of MIR17HG identified n-MYC and E2F1/2/3 significantly upregulated (p&amp;lt; 0.01). Additionally, utilizing sample-matched phospho-proteomics data, we found hyperphosphorylation of RB1, the upstream regulator of E2F, at three sites, providing additional evidence of RB1-E2F regulation upstream of MIR17HG. RB1 hyperphosphorylation and subsequent complete inactivation are mediated by the CDK2/Cyclin E complex, which is inhibited by the tumor suppressor p21. Interestingly, p21 (CDKN1A) gene expression was entirely depleted in the aggressive brain tumors group. In summary, our findings reveal the aberrant upregulation of the oncogenic miR-17/92 cluster in a group of aggressive brain tumors, potentially resulting from inactivating hyperphosphorylation of RB1 caused by p21 loss. This event frees E2F transcription factors and enables transcription of MIR17HG. Additionally, our study highlights E2F1/2/3 and CDK2 as potential therapeutic targets not only for aggressive brain tumors but also for other cancers overexpressing the miR-17/92 cluster. Future research will focus on molecular validation and targeting of the miR-17/92 regulatory pathway using available brain tumor cell line models.
CTNI-38. RACTAC TRIAL: PHASE II MULTICENTRIC ITALIAN TRIAL ON REPOSITIONING OF THE ANTIPSYCHOTIC DRUG CHLORPROMAZINE AND ITS COMBINATION WITH TEMOZOLOMIDE IN MGMT UNMETHYLATED GLIOBLASTOMA PATIENTS
Authors: Andrea Pace, Giuseppe Lombardi, Veronica Villani, Dario Benincasa, Claudia Abruzzese, Ilaria Cestonaro, Martina Corrà, Giulia Cerretti, Mario Caccese, Antonio Silvani, Paola Gaviani, Diana Giannarelli, Marco Paggi
Journal: Neuro-Oncology (2023)

Abstract The poor prognosis of patients affected by glioblastoma (GBM) prompts the search for more effective therapies, particularly for GBMs with unmethylated MGMT. Drug repurposing, can represent a safe and inexpensive way to bring novel pharmacological approaches from bench to bedside. Chlorpromazine, a medication in use for psychiatric disorders, shows in vitro features that make it eligible for repositioning in GBM therapy. In our experimentation on six GBM cell lines, chlorpromazine inhibited cell viability, induced polyploidy, reduced cloning efficiency as well as neurosphere formation. Moreover, chlorpromazine synergized with temozolomide, in reducing cell viability and cooperated in reducing cloning efficiency and inducing cell death. With these assumptions, we started a multicentric Phase II clinical trial on newly diagnosed GBM patients with unmethylated MGMT by adding chlorpromazine to temozolomide in the adjuvant phase of the standard first-line therapeutic protocol. The experimental procedure involves the combination of CPZ with standard treatment with TMZ in the adjuvant phase of the Stupp protocol. CPZ was administered orally at a dose of 50 mg/day – GG 1-28 – of every cycle of the adjuvant treatment with TMZ. . Efficacy outcomes were evaluated using Kaplan–Meier methodology. OS was measured from diagnosis to death; PFS was determined from radiotherapy to PD or death due to any cause. Between April 2020 and June 2022, 45 patients who met the eligibility requirements were screened. Forty-one patients received at least one cycle of treatment and were included in the analysis. 43 patients have been enrolled, 29 male, 12 female. 20 patients completed 6 cycles of treatment, without relevant toxicity. The results show a median PFS of 8 months (St.Dev. 5,7) and a median OS of 15 months (St.Dev. 6,9). The addition of Chlorpromazine to temozolomide was well tolerated in newly diagnosed Glioblastoma unmethylated patients, with promising impact on outcome measures.
Rapid Improvement in Recalcitrant Cutaneous Juvenile Dermatomyositis With Anifrolumab Treatment
Authors: Katharina S. Shaw, Diana B. Reusch, Rochelle L. Castillo, Kimberly B. Hashemi, Robert Sundel, Fatma Dedeoglu, Ruth Ann Vleugels
Journal: JAMA Dermatology (2023)

This case report describes a 14-year-old girl with juvenile dermatomyositis who presented with a 6-year history of a pruritic, photosensitive eruption involving her face, neck, trunk, and extremities and was successfully treated with anifrolumab.
RADT-12. GENOMIC CHARACTERISTICS AND CLINICAL OUTCOMES OF STEREOTACTIC RADIOSURGERY FOR COLORECTAL CANCER BRAIN METASTASES
Authors: Chengcheng Gui, Henry Walch, Kirin Mueller, Jordan Eichholz, Ishaani Khatri, Luke Del Balzo, Nancy Kemeny, Brandon Imber, Nikolaus Schultz, Michael Foote, Rona Yaeger, Luke Pike
Journal: Neuro-Oncology (2023)

Abstract PURPOSE Brain metastases (BM) from colorectal cancer (CRC) portend a limited prognosis but are poorly understood, both clinically and biologically. This study defined the clinical outcomes and genomic features of CRC BM treated with stereotactic radiosurgery (SRS). METHODS Patients with newly diagnosed CRC BM treated with SRS at a single institution between 2009 and 2022 were included. Next-generation targeted sequencing using MSK-IMPACT of at least one intracranial or extracranial tumor was required. Overall survival (OS) was evaluated using Kaplan-Meier analysis. Intracranial progression (IP) and local recurrence (LR) were evaluated using competing risk analysis, accounting for death. RESULTS We identified 124 patients with 304 BM, of which, 66 BM received SRS postoperatively. The median prescription was 27 Gy in 3 fractions. Median OS after SRS was 7 months. Poorer KPS, progressive extracranial disease, and lung metastases independently predicted poorer OS. Twelve months after SRS, cumulative incidences of IP and LR were 37% per patient and 6.1% per lesion treated, respectively. Three or more BM at diagnosis independently predicted earlier IP. Biologically effective dose less than the median predicted LR, independent of tumor size. Genomic data were obtained from 68 primary tumors, 63 extracranial metastases, and 33 BM. BM demonstrated significantly greater fraction genome altered, chromosomal instability, and TP53 alterations compared to extracranial metastases and primary tumors. Among patients who had IP, compared to those who had no IP within 6 months, BM contained more frequent alterations in KRAS (56% vs. 43%), SMAD4 (44% vs. 0%), and APC (77% vs. 57%). CONCLUSIONS Among CRC BM treated with SRS, OS and IP were correlated with extracranial and intracranial disease burden, and LR was correlated with SRS dose. Genomic characteristics differed between BM and extracranial disease, and between patients who did and did not experience IP. Further investigation of these genomic differences is underway.
EPID-14. ASSOCIATION OF ELEMENTAL IRON WITH GLIOBLASTOMA PATIENT OUTCOMES
Authors: Ganesh Shenoy, Madison Kuhn, Aurosman Sahu, Vladimir Khristov, Madison Heebner, Hannah Wilding, Taylor Clegg, Debarati Bhanja, Quinn Wade, Laura Liermann, Dongxiang Wang, Nataliya Smith, Chachrit Khunsriraksakul, Kondaiah Palsa, Becky Slage-Webb, Brad Zacharia, Elizabeth Proctor, James R Connor
Journal: Neuro-Oncology (2023)

Abstract Very few studies have examined the role of trace metals, such as iron, in glioblastoma biology and patient outcomes. Here we directly measured iron content in matched glioblastoma tumor and plasma samples using inductively coupled plasma mass spectroscopy (ICP-MS) or inductively coupled plasma atomic emission spectroscopy (ICP-AES), and then studied associations of iron with clinical parameters such as median overall survival (mOS). Elemental iron analysis was performed on a total of 31 glioblastoma samples, 21 of which had matched plasma samples that were analyzed together. Plasma samples from age-matched healthy volunteers were used as a control for comparisons against plasma from glioblastoma patients. Plasma samples from glioblastoma patients had higher levels of iron compared to age-matched healthy control samples (1307.2 ng/mL vs. 575.2 ng/mL, P = .000013). Among glioblastoma patients, higher levels of plasma iron were associated with prolonged survival (mOS: 20.7 months vs. 12.4 months, P = 0.0063). Plasma iron levels, however, were not significantly correlated with tumoral iron levels (R = 0.095, P = 0.70), indicative of regulation between plasma and brain iron. Unsurprisingly, high tumor iron content failed to significantly associate with survival. To gain insights into whether iron may be associated with immune function, we analyzed plasma samples with multiplexed immunoassays. Glioblastoma plasma samples that contained higher levels of iron were associated with increased IFN-β (10.91 pg/mL vs 7.43 pg/mL, P = 0.004) and PDGF-AB/BB (1275.3 pg/mL vs 492.8 pg/mL, P = 0.009), whereas no such association was observed in healthy plasma samples. Our results demonstrate that plasma iron is associated with clinical outcomes and potentially with alterations in IFN-β and/or PDGF-AB/BB signaling in glioblastoma patients. These findings illustrate the importance of iron in glioblastoma biology and demonstrate its potential prognostic value.
IMMU-30. NOVEL HYPOMETHYLATING AGENT GSK-3484862 SENSITIZES GLIOBLASTOMA TO NY-ESO-1 SPECIFIC IMMUNOTHERAPY
Authors: Kevin Li, Thomas Lai, Robert Prins, Richard Everson
Journal: Neuro-Oncology (2023)

Abstract INTROUCTION Immunotherapy is a promising mode of treatment due to its specificity and efficacy in eliminating tumors, but is limited in GBM due to the lack of immunogenicity and unique cancer antigen expression. Previous work from our group has shown that Decitabine (DAC), a demethylating agent, can improve the immunogenicity of Glioblastoma (GBM) for immuno-therapeutic targeting through the upregulation of immunogenic cancer testis antigens (CTA) such as NY-ESO-1 and altered expression of other immunoregulatory programs. However, immunosensitization using DAC is limited due to non-specific toxicity after prolonged administration. We hypothesize that a newly synthesized hypomethylating agent, GSK-3484862 (GSK), may be an effective alternative to DAC in promoting CTA expression in GBM with limited cytotoxic effects on surrounding immune cells. METHODS Human GBM cells and patient-derived glioma spheres were treated with GSK and DAC. We investigated the differential expression in NY-ESO-1 at a transcriptional level between DAC and GSK through quantitative real-time PCR. To assess whether these differences translated into heightened immune responses as a result of NY-ESO-1 upregulation, we co-cultured DAC and GSK-treated immortalized and primary cell lines with transduced NY-ESO-1 specific T-cell receptor T-cells. RESULTS Immortalized and primary glioma sphere cells demonstrated equivalent NY-ESO-1 gene upregulation after four days of treatment between 1 µM DAC and 5 µM GSK. Glioma spheres treated for three weeks at a dose of either 0.5 µM DAC or 2.5 µM GSK demonstrate equivalent NY-ESO-1 upregulation. Furthermore, xCELLigence data demonstrates that equivalent NY-ESO-1 expression achieved by the differential dosing between GSK and DAC leads to similar rates of NY-ESO-1 specific T-cell mediated killing, indicating a functional equivalence between GSK and DAC induced immunosensitization at equivalent NY-ESO-1 expression levels. CONCLUSION Our results demonstrate a preclinical rationale for the use of GSK as a viable pro-antigenic agent for the sensitization of GBM to targeted immune therapy.
TMIC-21. SPHINGOSINE-1-PHOSPHATE RECEPTOR 3 (S1PR3) IN THE GLIOBLASTOMA TUMOR MICROENVIRONMENT MAY PLAY A ROLE IN IMMUNOSUPPRESSION
Authors: Sharon Michelhaugh, Jennifer Munson
Journal: Neuro-Oncology (2023)

Abstract Glioblastoma remains an intractable clinical problem with few efficacious treatments and poor patient outcomes because of the challenge in treating the tumor cells that have invaded into the normal brain. These invasive tumor cells typically remain after standard-of-care surgical resection and likely persist to generate recurrent tumors. In our previous studies of the glioma tumor microenvironment (TME), we identified sphingosine-1-phosphate receptor 3 (S1PR3) as upregulated in glioma TME regions with increased fluid flow. In order to efficiently study S1PR3 in the normal brain/ glioblastoma tumor interface, we engaged the Wake Forest University Brain Tumor Center of Excellence to construct a tissue microarray (TMA) including glioblastoma tissue cores specifically of the normal brain/ tumor interface as determined by pathologist review. The TMA included FFPE tissue cores from 42 GBM patients (average age 67.7 ± 10.9 years, 25 male, 17 female). Immunohistochemistry to detect S1PR3 was performed using an antibody that targets the amino-terminal domain followed by spatial profiling using neuroscience, neuroinflammation, and immune antibody panels (Akoya Biosciences). Preliminary analyses of the spatial profiling revealed 34 evaluable tissue cores, with no difference in the percentage of neurons, glial cells, vascular cells, or T cells between the S1PR3 positive and negative cores, however a significant difference in the percentage of M1 macrophages/ antigen presenting cells was found between the two groups (S1PR3-positive 0.646 ± 0.569%, n=13; S1PR3-negative 2.95 ± 3.28%, n=21, p=0.0178 two-tailed t-test. These findings suggest that the presence of S1PR3 may be associated with reduced M1 macrophages/ antigen presenting cells and therefore S1PR3 may contribute to glioblastoma tumor associated immunosuppression.
EPCO-02. DNA METHYLATION PROFILING OF BRAIN METASTASIS REVEALS UNDERLING TUMOR RECURRENCE SIGNAL AND ASSOCIATED PATHWAYS
Authors: Andrew Ajisebutu, Julio Sosa, Jeffery Zuccato, Jeff Liu, Vikas Patil, Gelareh Zadeh
Journal: Neuro-Oncology (2023)

Abstract INTRODUCTION Brain metastases, the most common form of intracranial neoplasms, carry a poor survival rate, mostly attributed to their high recurrence rates. Currently there are no reliable methods to determine which patients will progress. DNA methylation profiling (DNAmp) has become a useful tool in the diagnosis and stratification of intracranial neoplasms, and has the potential to provide clues on the epigenetic mechanisms that govern tumor behavior. METHODS A cohort of 58 BM tumor samples were selected for analysis. The cohort was composed of three groups: N=21 primary metastatic tumors (PMT), N=21 matched paired recurrent tumors (RMT), and a cohort of N= 16 primary metastatic tumors without any evidence of recurrence (NRMT). All tumor samples underwent DNAmp on the Illumina Infinium EPIC array to determine their methylation status at 850,000 CpG sites. Tumors were profiled via unsupervised hierarchical clustering, pathway enrichment analysis, and cell deconvolution analysis. RESULTS Differential methylation analysis revealed over 32617 differentially methylated CpG sites between grouped PMT and RMT samples, and 835424 sites between PMT and NRMT samples. When comparing PMT with NRMT samples, we revealed a distinct DNAmp that was upheld upon hierarchical clustering analysis. NRMT samples show a significant downregulation of pathways involved in DNA-binding and transcriptional regulation. Paired analysis of PMT and RMT revealed a relative paucity of differentially methylated CpG sites shared across paired samples: a total of 257 probes were differentially methylated across 14/19 samples. These probes however showed enrichment primarily for DNA-binding and transcription factor regulation, in reverse from the non-recurrent samples. CONCLUSION Our data suggests that DNAmp may be capable of differentiating tumors destined to progress from those with less aggressive features, and that DNAmp appear to remain stable through to recurrence. This work demonstrates the potential for DNA methylation to be utilized to uncover pathways associated with BM recurrence.
EXTH-84. INTRATUMORAL IL-12 DELIVERY VIA MESENCHYMAL STEM CELLS COMBINED WITH PD-1 BLOCKADE LEADS TO LONG-TERM ANTITUMOR IMMUNITY IN A MOUSE GLIOBLASTOMA MODEL
Authors: Stephen Ahn
Journal: Neuro-Oncology (2023)

Abstract Although PD-1 blockade is effective for treating several types of cancer, the efficacy of this agent in glioblastoma is largely limited. To overcome non-responders and the immunosuppressive tumor microenvironment, combinational immunotherapeutic strategies with anti-PD-1 need to be considered. Here, we developed IL-12-secreting mesenchymal stem cells (MSC_IL-12) with glioblastoma tropism and evaluated the therapeutic effects of anti-PD-1, MSC_IL-12, and their combination against glioblastoma using an immunocompetent mouse orthotopic model. Anti-PD-1 and MSC_IL-12 showed complete tumor remission in 25.0% (4/16) and 23.1% (3/13) of glioblastoma-implanted mice, respectively, and their combination yielded synergistic antitumor efficacy indicated by 50.0% (6/12) of complete tumor remission. Analyses of tumor-infiltrating lymphocytes using immunofluorescent imaging revealed that anti-PD-1 increased CD8+ T cells, while MSC_IL-12 led to infiltration of CD4+ T cells and NK cells. Both therapies reduced frequencies of Tregs. All these aspects observed in each monotherapy group were superimposed in the combination group. Notably, no tumor growth was observed upon rechallenge in cured mice, indicating long-term immunity against glioblastoma provoked by the therapies. Single-cell RNA-seq of mouse brains confirmed these results and revealed that the combined treatment led to immune-favorable tumor microenvironment–CD4+, CD8+ T cells, effector memory T cells, and activated microglia were increased, whereas exhausted T cells, Tregs, and M2 polarized microglia were reduced. Taken together, anti-PD-1 and MSC_IL-12 monotherapies show long-term therapeutic responses, and their combination further enhances antitumor efficacy against glioblastoma via inducing immune-favorable tumor microenvironment.
CTNI-34. ZOTIRACICLIB (TG02) FOR NEWLY DIAGNOSED GLIOBLASTOMA IN THE ELDERLY OR FOR RECURRENT GLIOBLASTOMA: FINAL RESULTS OF THE EORTC 1608 STEAM TRIAL
Authors: Emilie Le Rhun, Thierry Gorlia, Jörg Felsberg, Julia Furtner, Joost Jongen, Claude-Alain Maurage, Francois Ducray, Patrick Roth, Peter Hau, Olivier Chinot, Matthias Preusser, Stephanie Cartalat, Martin van den Bent, Maike Collienne, Guido Reifenberger, Michael Weller
Journal: Neuro-Oncology (2023)

Abstract BACKGROUND Zotiraciclib (TG02) is an oral multi-cyclin dependent kinase (CDK) inhibitor that is supposed to suppress tumor growth via CDK-9-dependent depletion of survival proteins such as c-MYC and MCL-1 which are frequently overexpressed in glioblastoma. METHODS EORTC 1608 (NCT03224104) (STEAM) had a three parallel group (A,B,C) phase Ib, open-label, non-randomized, multicenter design. Groups A and B explored the maximum tolerated dose (MTD) of TG02 in elderly patients with IDH1R132H-non-mutant newly diagnosed glioblastoma or anaplastic astrocytoma, in combination with hypofractionated radiotherapy alone (group A) or temozolomide alone (group B), based on O6-methylguanine DNA methyltransferase promoter methylation status determined centrally. Group C explored single agent activity of TG02 in IDH1R132H-non-mutant glioblastoma or anaplastic astrocytoma at first relapse after temozolomide chemoradiotherapy with a primary endpoint of progression-free survival at 6 months. Secondary objectives included efficacy, quality of life, and safety. Expression of CDK-9, c-MYC and MCL-1 was determined by immunohistochemistry. RESULTS The MTD was 150 mg twice weekly in combination with radiotherapy alone (group A) or temozolomide alone (group B) in elderly patients. Two dose-limiting toxicities were observed at 150 mg, one in group A (grade 3 seizure) and one in group B (multiple grade 1 events). Main toxicities included neutropenia, gastrointestinal disorders, and hepatotoxicity. Progression-free survival at 6 months in group C was 6.7%. CDK9 and its indirect targets, c-MYC and MCL-1, were confirmed to be expressed and their expression was correlated, supporting a regulatory role for CDK-9. The protein levels of CDK-9 and MCL-1 correlated with overall survival. CONCLUSION TG02 exhibits overlapping toxicity with alkylating agents and low clinical activity as a single agent. Larger randomized trials are required to explore activity in combination with RT or TMZ. The role of CDK-9 and its down-stream effectors as prognostic factors and therapeutic targets in glioblastoma warrants further study.
TMIC-60. CROSS-SPECIES ANALYSIS OF HUMAN AND NEW MOUSE MODELS OF GBM SUBTYPES IDENTIFIES VISTA AS A PROMISING IMMUNOTHERAPY TARGET
Authors: Jose Madonado, Caiyi Wang, Jia-Shiun Leu, Thomas Wong, Nourhan Abdelfattah, Thomas Gallup, Jihye Paik, Massimo Squatrito, Kyuson Yun
Journal: Neuro-Oncology (2023)

Abstract Immunotherapy is a promising treatment modality for GBM; however, clinical trials thus far have failed to provide significant clinical benefit to most patients. GBM is one of the “immune cold” tumors characterized by poor infiltration of T cells and the abundance of immune-suppressive myeloid cells that block T cell infiltration and/or activation. A major bottleneck to developing more effective immunotherapies is the paucity of faithful preclinical models to discover and validate new treatments. Here, we report multi-dimensional analyses of six different transplantable mouse glioma models in the C57BL6/J background that represent the three human GBM molecular subtypes. We performed whole exome sequencing, STR fingerprinting, immune phenotyping, and single-cell RNA-sequencing of each model and confirmed that the new models exhibit highly heterogeneous and immune suppressive TME, similar to human GBM. In addition, we performed cross-species comparisons of glioma and immune cell subtypes between human and mouse GBMs at the single-cell level and demonstrate strong concordances in molecular phenotypes and cellular heterogeneity. These result in qualitative and quantitative differences in the cell: cell communication among different stromal cells and glioma cells in each model, and we propose that these interactions shape the local niche and immune suppressive neighborhoods. Notably, in both human tissues and mouse models, PD1/PDL1 expression is low or sporadic, and, unlike the GL261 model, the new mouse models are resistant to anti-PD1 and CTLA4 treatment in vivo. Finally, we discovered that VISTA is a widely expressed immune checkpoint in both human and mouse GBM and demonstrate the efficacy of anti-VISTA and anti-PD1 combination therapy in the most immune-suppressive mouse model. In summary, we demonstrate the utility of these immune-competent mouse models and nominate anti-VISTA+PD1 treatment as a promising novel combination therapy for GBM.